I agree with Stephen. WTpart is the object defining your product. The definition is made of CAD data and also Documents. Therefore it is very rare to have the version of the WTpart the same than the CAD model.
If you do not use any other type of object in your WTpart than the CAD data, why do you need WTpart ?
The other issue you relate is from my point of view more important. You should not be able to revise a model if you do not revise the WTpart. Since the model is part of your product definition, if you change it, you change your product definition and therefore your WTpart. We have not find a way to force the user revising (and changing the state of the WTpart at the same time than its content and accordingly). My admin set up the setting for the dependent object to always be automatically collected.
Hope this helps
Have you ever thought that your WTPart Process and your CAD document process is different. WTPart follows fit, form and function. While CAD documents can change with any modification to the CAD file that has no changes to fit, form and function. Constantly changing WTPart to sync to your CAD may not be the best practice of solutions. Small changes in the file management may have dramatic changes in the entire enterprise. It is best now to package your changes in ECNs of PLM.
You have to break away from file management methodology when dealing with WTParts because it affects the entire organization. Pro/E file or any CAD file/tool management methodology should not break basic engineering principles of form, fit and function. Sometimes, you should just not revise any more after it has been released for detail inseparable components. Just create a new WTPart and save as for CAD.
A related question I have is, what CAD documents get a WTPart?
With using auto-associate you get WTParts for every CAD document. But does every CAD document need a WTPart?
Obvious example, a sheetmetal part with a flat pattern as an instance, the flat pattern instance doesn't need a WTPart, but with auto-associate, it gets one.
CAD / PLM Manager
Since Version 10 there are preferences available to control this behaviour together with some CAD Parameters
Look for Part Structure Override Attribute Name and Phantom Assembly Override Attribute Name